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Can I overheat my MacBook Air if I close its lid and use external monitor?

Discussion in 'MacBook Air' started by lexicaller, Feb 8, 2013.

  1. macrumors newbie

    Hello ALL!
    I am very new in Mac World, comming from many years in Linux-on-ThinkPads World. (My main reason to switch is no time for maintenance and need for Unix!)

    Anyway, I started to use my MacBook Air with an external monitor and with closed lid (clamp-shell mode?). Then, a colleague warn me that this way I may cause overheating. My machine should be quite good (i7, 4GB, 256SSD), but I am doing excesive data analysis.

    So, my question is: Is my colleague right? Should I leave lid open? If closed, I should never do demanding stuff?

    Many thanks!
  2. macrumors demi-god


    Your colleague is wrong. It's perfectly safe to operate in clamshell mode, as Mac notebooks are designed to do just that.

    Heat radiates in all directions and dissipates through the aluminum body. While clamshell mode or using a keyboard covering slightly inhibits dissipation, it's not enough to cause problems or raise temps more than a few degrees, since the primary cooling is through the vents.

    There has never been any air intake or exhaust vents through the keyboard on any Mac notebook. For all Mac notebooks except the MBP-Retina, both intake and exhaust has always been through the vents in the rear near the hinge. The new MBP-Retina has intake vents along the sides at the bottom and exhaust through the rear vents, near the hinge.

    Learn about the fans in your Mac
    This arrangement allows for venting with the lid open or closed (for operating in clamshell mode). There is a solid panel under the keyboard, preventing any meaningful airflow.
  3. macrumors 68020

    Cheffy Dave

    Ah, ya beat me GGJ;)
  4. macrumors 68040


    Yes, absolutely.
    For example, if you close the lid, use an external monitor and place it on a radiator. :p
  5. lexicaller, Feb 8, 2013
    Last edited: Feb 9, 2013

    macrumors newbie

    Many thanks GGJstudios! Your post is convincing and calming!

    iSee, it's not nice to make fun with poor souls and ignorants :p

  6. Intell, Feb 8, 2013
    Last edited: Feb 8, 2013

    macrumors P6


    This statement isn't accurate. The non-unibody Macbooks have many holes in their keyboard to allow air to be pulled in through them. They have a high concentration of the holes over the fan and extending out over the logicboard. While the image below is of a bare 2008 Macbook, the 2006 and 2007 ones have more vent holes in the middle part of the keyboard area just over the fan.

    Image source: https://secure.flickr.com/photos/34268406@N06/3188462923/in/set-72157612409546653
  7. macrumors newbie

    So, then, what should I do?!? :confused:
  8. macrumors demi-god


    Read the manual. It's 100% safe
  9. macrumors 6502a

    If it's 100% safe, why doesn't Apple allow you to close the laptop and have it not go to sleep. Unless I'm mistaken, you need to force the computer to stay awake by way of a hack.
  10. macrumors P6


    Unless you have a non-unibody Macbook, you're fine. Use it as you see fit.

    No hacks are needed. Just plug in an external monitor, mouse, and keyboard and it'll wake up. This is how it's been since the 1990's and Apple laptops.
  11. macrumors 65816

    Don't be confused by the back and forth here - it is COMPLETELY safe, and an expected use of the Air. I do it all the time, and have for years.
  12. hfg
    macrumors 68030


    This is correct ... and I think it requires the AC adapter to be attached and powering the computer in order to enter the "Clamshell" mode.

  13. macrumors 6502a


    My question for you: WHY would you WANT to close the lid? I'm typing this to you on an external 23" monitor plugged in to my MBP... but my MBP is open so that I have it's 15" monitor available to me also. Why go out of your way to deny yourself a dual-monitor setup?
    And if it's because you don't want to use the built-in monitor as your primary, that's fine. Just change the primary monitor to the external in your System Prefs, and that way your dock and menu bar show up on the larger monitor. But that way you still have the built-in display to hold an extra window or two.
  14. macrumors G5


    Apple does that because you cannot access the keyboard, and you cannot see the screen, so the computer is not useable. To keep the MacBook awake you don't need any hack, just plug in any old USB keyboard and monitor.
  15. macrumors 68020


    Because then your GPU is being split between two monitors rather than just powering the one external. And while dual monitor setups are great, they aren't always necessary.
  16. macrumors regular

    This is an excellent question. Why doesn't Apple allow your computer to run with the lid closed under normal circumstances? I use a special app called "Caffeine" to allow my mac to run with the lid closed (to play music, etc.). I ran some google searches to see why Apple would not allow users to do this without using third-party apps, and most of the responses said that Apple does this to prevent you from overheating your computer.

    You've misunderstood the post you're replying to. The point is that you need a "hack" (a third-party app) to allow your mac to run with the lid closed WITHOUT an external monitor.

    You say that "the computer is not useable," but that is only because Apple has designed it in such a way. My old windows laptops were never unuseable just because the lid was closed - same goes for my Macbook with the caffiene app installed.
  17. macrumors 6502a

    So this would suggest that operating with the lid closed can indeed cause your Mac to overheat...?
  18. macrumors regular

    Well, you clipped the quote. The full quote includes: "... most of the responses said that Apple does this to prevent you from overheating your computer."

    So, it could suggest that operating with the lid closed can indeed cause your Mac to overheat. But it could also suggest that the people who said that don't know what they're talking about.
  19. macrumors demi-god


    Because 9/10 people expect there laptop to sleep or power off on a lid close. Add a mechanical drive into the mix and it could be damaged in the process.
  20. macrumors 65816


    You're unable to overheat any modern computer. It will automatically turn off if the temperature gets too high.
  21. macrumors regular

    Lid close = sleep could easily be the default setting while also allowing for other settings (as in Windows laptops).
  22. macrumors demi-god


    Those are not vents. The vents are located in the rear. That is a picture from a white MacBook being modified by a user. Those holes are covered by keys and are not used as vents for cooling the MacBook. If they were, Apple would never recommend using clamshell mode, which would block vents. While non-unibody models did have some holes in the keyboards, they were not used as vents. Naturally, some incidental airflow may have occurred in such older models, but not enough to affect primary cooling, which has always been through the intake and exhaust vents at the rear, near the hinge.

    You should use clamshell mode whenever you need or want to without worry. There is no venting through your keyboard.
  23. macrumors P6


    The holes in the back are the primary vents with the ones in the keyboard being the secondary vents. The way you phrased your statement makes it out as being that the holes were put there by the user, they were not. The keyboard and the keyboard circuit ribbon do not block those holes. Apple designed those holes to correspond with other holes so that the holes in the metal top case line up with holes in the circuit ribbon and are in the keywell. Air is pulled in around the keys and through the keywells into the case. Running a non-unibody Macbook in clamshell mode results in the fan coming on more frequently and staying on longer. It also results in the GMA950 throttling down due to too much heat within the case. The same things happen when a keyboard skin is used. I chose that picture to illustrate that there are indeed vent holes in that model Macbook.
  24. GGJstudios, Feb 11, 2013
    Last edited: Feb 11, 2013

    macrumors demi-god


    Nonsense. It depends on the workload entirely. I can run for weeks in clamshell mode on my non-unibody MBP and the fans stay at the minimum and temps are within around 5 degrees of normal. Only when I put a heavy load on the system do temps rise and fans spin up, which happens whether in clamshell mode or not. Any airflow is incidental and is not depended on for cooling. If this were not true, Apple would advise against running in clamshell mode for those models. As it is, they don't, because any temp changes are minimal and likely caused mostly by inhibiting dissipation, not venting through the keyboard.

    Learn about the fans in your Mac
    Hopefully we can get back on topic, as this thread is about a MBA, which has a solid panel under the keyboard, preventing any air flow.
  25. macrumors P6


    The Macbook Pros, as you state to use, don't have any vent holes in their keyboard. That's why you are able to use it without much heat increase. The Macbooks in question have the vent holes and need them for optimal performance. Apple knows about this limitation and that's why the GMA950 downclocks to 250Mhz from its default of 400Mhz when in clamshell mode. Your overall knowledge with these Macbooks seems to indicate that you have never used one for very long or examined one's interior in great detail. The article you posted indicates air exit vents, not air intake vents. It fails to mention the Mac Pro's intake vent at the front of the machine or the Mac Mini's and iMac's intake at the bottom.

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